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16  Using Arduino / Project Guidance / Attaching interrupts to multiple pins on: January 28, 2013, 12:33:40 pm
I'm trying to measure how long it takes each digital input to go from low to high. Can an Arduino Mega be programmed to have separate interrupts attached to each of its digital pins, to detect a level change? Or would you just constantly read pin values in the main loop() and check for the change there?
17  Using Arduino / Sensors / Re: Waterproof sensor plug on: January 23, 2013, 10:08:06 pm
theres this new thing out called a tarp........lol

You know how I can tell you've never designed any devices for outdoor use?

OH YEAH? well only one follows the sun but im not done yet. and i cant get it to turn a corner.

That's probably because it's all wet. You forgot the tarp. lol
18  Using Arduino / Sensors / Re: Waterproof sensor plug on: January 23, 2013, 06:19:09 pm
theres this new thing out called a tarp........lol

You know how I can tell you've never designed any devices for outdoor use?
19  Using Arduino / Project Guidance / Best Arduino for lots of ADC on: January 23, 2013, 12:03:07 pm
I'm looking for an arduino/shield combo capable of at least 10 ADC channels. The Mega has 16, but is a bit expensive, and includes a lot of other features I don't need. Is there a cheaper arduino with just as many ADC pins, or some shield that provides more ADC pins?
20  Using Arduino / Sensors / Waterproof sensor plug on: January 23, 2013, 11:58:52 am
Can anyone recommend a cheap waterproof "plug" to use for wiring an external sensor to a case-enclosed arduino?

I'm planning an outdoor application where the arduino sits in a waterproof case, exposed to the elements, with up to 12 4-pin analog sensors individually extending from the case. The arduino will be wired to 12 female plugs on the inside of the case, and the actual sensor/cable will connect via a male plug on the outside of the case. Not all sensor plugs will be used, so I need to plug to be waterproof even if nothing's plugged into it.

Googling finds tons of plugs, but most are $20-30 a piece and designed for high-end industrial applications. Where would I find something cheaper, geared more towards a consumer application?
21  Community / Products and Services / Re: WIFI Shield for Arduino on: January 23, 2013, 10:54:20 am
@Cerin

The pictures above are of an older version of this hardware.  Our most recent version, the only version we currently sell, now features headers.


Thanks for the correction.
22  Community / Products and Services / Re: WIFI Shield for Arduino on: January 23, 2013, 09:08:18 am
The much lower price than the "official" wifi shield (and actually being in stock) makes it attractive, but honestly, I'll probably never buy one because of its lack of top headers. Using that shield means you can't use any other shield, which is a deal breaker for a lot of projects.
23  Using Arduino / Sensors / Re: How to weatherproof sensors on: January 19, 2013, 06:25:24 pm
Just my 2 cents... Use capacitance to measure moisture, this allows you to completely seal the unit and you don't have to use expensive metals for the tester. Also, use a decent connector and dielectric grease in the connector. The grease is the kind they use to keep the elements out of spark-plugs and buried telephone line junctions and such.

Does anyone sell these at a reasonable price in a form I can easily connect to an Arduino's ADC port? Googling doesn't find much, and the few I can find, like this, don't have any price listed...which usually means they're insanely expensive. I have a budget of a couple hundred dollars, and it looks like a single "good" capacitive soil moisture sensor may well cost much more than that.
24  Using Arduino / Motors, Mechanics, and Power / Re: Monitoring and Charging Multiple Batteries on: January 18, 2013, 09:21:47 am
Would it be feasible to hook up the load outputs (not the battery hookups!) of two 3.7 USB Lipo chargers (e.g. this or this) in series to effectively get a 6-7V rechargeable Lipo power supply?
25  Using Arduino / Sensors / Re: How to weatherproof sensors on: January 18, 2013, 08:34:38 am
If you seal the sensor , so that it is waterproof,   then the soil moisture and humidity won't be able
to get into it.   
I suspect that a completely waterproof solution is not what you actually want, for your stated application.

True. I was referring to the above-ground part of the sensor, especially the plug. I'm not too worried about the below-ground parts, as long as the leads are gold-plated or similarly protected against corrosion.
26  Using Arduino / Motors, Mechanics, and Power / Re: Monitoring and Charging Multiple Batteries on: January 17, 2013, 03:54:27 pm
Are you using anything like a solar charger shield? Can those use an arbitrary external power source instead of a solar panel to recharge the battery?

That shield is designed specifically for a single cell lithium battery. Can't change the output voltage.

To charge a lead acid battery a ready made solution would be called an "on board battery charger" (example). In real world use they are designed to stay permanently attached to a car/boat and then plugged in to a wall socket to maintain the battery.

For a non-ready-made solution I'd look at something like a UC3906. Lots of examples from Mr. Google on this.

Thanks, but I was referring to the *input* source, not the output. e.g. charging the single lithium from a wall supply instead of a solar panel. If it expects a certain voltage/amperage from the solar panel, what would be the problem in getting that instead from a wall adapter?
27  Using Arduino / Project Guidance / Re: Wiring Recommendations on: January 17, 2013, 11:05:22 am
Yes with only three ground pins and two 5V pins wiring up lots of sensors and external components can get messy in a hurry. It's not a problem if you are building your stuff onto a solderless breadboard, but that is not a good long term solution for many projects. The clever Asians have had a nice solution for some time now and I bought one a couple of years ago and use it often to wire up stuff quickly for a proof of concept test or whatever.

http://www.ebay.com/itm/Sensor-Shield-V4-Digital-Analog-Module-Servo-Motor-For-Arduino-UNO-Duemilanove-/130693385943?pt=LH_DefaultDomain_0&hash=item1e6deeced7

Lefty

Thanks for the link. Yeah, as I research all the available shields out there, I'm seeing several "sensor" and "IO" shields that would likely make things a lot cleaner.
28  Using Arduino / Sensors / How to weatherproof sensors on: January 17, 2013, 11:00:25 am
I'm working on a project to measure soil dryness in multiple outdoor potted plants, and I'm looking for a moisture sensor that can withstand the elements. I'm found several stores selling sensors like this, but I can't imagine that thing lasting more than a couple weeks outside before sun and rain destroy all the exposed contacts.

Is anyone aware of other cheap but robust moisture sensors? How would I weather proof the sensor?
29  Using Arduino / Motors, Mechanics, and Power / Re: Monitoring and Charging Multiple Batteries on: January 17, 2013, 12:18:48 am
oh! I thought you were using a seperate supply for the motors
Quote
and charge both the netbook's battery and the additional 12V battery (likely lipo) simultaneously.
I'm making something similar ATM (no laptop), but using a solar panel to charge a 12V gel battery. Power requirements should be within daily charge capability, but I will be adding a sun-bathing routine if the bat gets low. I'll put the panel at optimum angle and allow the unit to rotate toward the sun. Bit dark for testing at the moment smiley-wink So waiting for the spring.  smiley-razz Continuous activity is not necessary as this is an exercise in navigation rather doing any useful work. For that I will probably aim to set up a self serve "fuelling point" as the area available will not allow a high enough current density from a PV panel.

Good luck

Are you using anything like a solar charger shield? Can those use an arbitrary external power source instead of a solar panel to recharge the battery?
30  Using Arduino / Motors, Mechanics, and Power / Re: Monitoring and Charging Multiple Batteries on: January 16, 2013, 02:12:57 pm
Nevermind. As the designer mentions here, "it wasn't designed to be charging and powering the circuit in the same switch position." It also requires a manual switch be flipped to initiate charging, which makes it useless for UPS and robotics applications.

*sigh*

So close.
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